These minutes represent a summary of the proceedings of the 2^nd PIN meeting. They are being made available on the PIN web site, (see below), where some of the overheads from speakers will also be accessible.

Introductory Talks: Following a welcome from Steve Flynn of the DTI, Colin Ramshaw of Newcastle University answered the query ‘PI – What’s New?’ He said that the first influencing factor were capital cost savings, associated with the total cost of the system. A second influence was intrinsic safety, with reduced inventory being a key factor for PI here. The ‘next wave’ of PI applications is increasingly associated with environmental awareness – clean/green technologies. There are implications for energy conservation, and CO₂ reduction at source/sequestration. For example, in a refinery, 60% of CO₂ emissions are associated with the catalytic cracker. In a nutshell ‘PI is all about creating the correct fluid dynamic environment for making the chemistry and kinetics go as fast as they can and go where we want them to.’ Colin also affirmed that we have the skills to help develop the technologies, and the opportunities are huge.

David Reay then updated members with his talk ‘PIN-What’s New?’ The mailing list of members was approaching 200 (now exceeded) and over 30 were from Europe, the USA or the Far East. The Web page (http://www.ncl.ac.uk/pin/) was running well, but needed more data from members, and a second issue of PIN News was being prepared. A PI Guide was being considered, with support from HSE, DTI and possibly ETSU. This would commence with a scoping study, and members will be contacted about this in due course. The Committee was discussing introducing membership subscriptions, possibly based on a charge per meeting. This will be discussed in the next PIN News, after a further committee meeting.

Technical Session: The Dutch PI Group and their case study output was presented by Henk van den Berg. Founded over two years ago, the group sees itself as having a major role in addressing the next step in energy reduction in the process industries, where a 20% saving has been made for 1989-2000. The partners in the PI Group are 8 industrial companies, two engineering firms and three institutions. The role of the task force is to communicate PI concepts and successes, by tracing new technologies, promoting demonstrations and establishing pilot demo. units. Case studies have formed an important part of the activity. Henk said that originally the platform aimed to be pre-competitive, but once something of value appeared for a participant, publicity was less popular. The case studies involved Lyondell (on MTBE processes), with a view to reducing CO₂ emissions, DSM, looking at what a plant in 2020 might look like, and Shell with PDC (Process Design Centre), using PROSYN software to examine benefits in some processes. TNO with Inspec Fine Chemicals/Laporte looked at the production of glycidylethers.

The Lyondell study involved brainstorming, pinch and exergy analyses, and covered technologies such as membranes, intensive heat exchangers, reactive distillation and combined unit operations. The results involved creating awareness and concepts, for now, with benefits for grass routes situations and long term development needs. The DSM approach was different, aiming at new technologies but appreciating that CO₂ reductions were politically desirable. Goals were set, in particular a 30% reduction in capital expenditure (CAPEX). A systematic redesign, starting with reactor systems and asking what each unit operation needed to do, led to a reduction in the number of unit operations by about 50%. Critical issues were identified, including the availability of alternative processes. The 30% CAPEX reduction was achieved by the multi-disciplinary team. DSM also looked at applying process synthesis techniques to existing plants. One message obtained during a successful study along these lines (saving a projected 30 million Guilders on a revamp) was that the ‘Not Invented Here’ (NIH) attitude should be avoided. Another useful team planning point was that a mixed team was best, including representatives from the business side.

The PDC study suggested that Shell could, for example, benefit from a 50% CAPEX reduction, 16% variable cost reduction, and 2 million Guilders/a energy cost savings. TNO looked at the sensitivity of product specification to process variables and other parameters. This led to recommended alternative synthesis routes, improved reaction/separations, and integrated unit operations.

Henk said that the lessons of the two year exercise (to date) were primarily that communication was a very important issue. Process systems engineering tools were very valuable, and the support of NOVEM (quasi-Governmental funding body) was essential. He concluded that good process engineering companies can successfully accept the challenge afforded by PI.

Arthur Gough (Newcastle University) and Asterios Gavriliidis (UCL) described recent work on micro-reactors. In the catalytic plate reactor, the catalyst forms a <50 micron layer on the heat exchanger surface. The plate is typically 0.5 mm thick, with 2 mm channels. Good control and heat & mass transfer are achieved. Fluxes are 10 kW/m², with a 1 K deltaT between reactant and fluid. Reactions studied are selective hydrogenations, oxidation, Fischer-Tropsch and Syngas from methane. Endothermic reactions such as methane reforming and paraffin dehydrogenation are possible. Data were given on the fluxes achieved and catalysts used on the combustion and reforming sides of the reactors, and the question remaining was whether the reactor could behave in a stable manner when a reaction was taking place on both sides of the plates. Asterios reported on model data for methane combustion/stream reforming and methane combustion/ethane dehydrogenation. He highlighted some hot spots and ways of overcoming these albeit at the expense of conversion. Other factors affecting the formation of hot spots include the thermal conductivity of the wall – if it is reduced a delta T between the combustion and e.g. dehydrogenation reactions appears, and this is coincident with hot spots occurring. It was concluded that the ratio of catalyst loading was a key parameter in compact plate reactor operation. Careful design was needed t avoid parametric sensitivity, hot spots etc.

The ‘Laboratory on a Chip’ was discussed by Simon Cowan, of the Laboratory of the Government Chemist. Here he said we were looking at an order of magnitude reduction in channel size compared to the previous talk, with feature sizes of the order of tens of microns. The lead had been taken by biological/pharmaceutical companies and those in the area of medical diagnostics. Drivers included the need to have high throughput with low cost, and reduced power and reagent use in the lab. Faster measurements are possible and reactions are more efficient.

The ‘enabling’ technology is microfabrication, which grew up with the electronics industry. Techniques such as lithography, etching and associated bonding methods allow this. Although expensive to establish, with clean rooms etc., mass production of the product can lead to substantial reductions in unit cost. An ‘on the chip’ liquid chromatography column measures 20 x 20 x 500 mm. The channel cross-section is easy to control using the above manufacturing methods. Simon gave several examples, the first being developed at Stanford University in 1979, for chromatography, the benefit being speed of analysis. Using electrophoresis/electro-osmotic flows to separate amino acids, the analysis time is much lower on a chip than with a bench top system, without degrading resolution – better heat dissipation brings about this benefit. The University of Twente (NL) has developed a reactor, with IC London, with 50 microlitre volume. Effective in use, it has good thermal transfer and mixing, and is easy to scale up via parallel synthesis. It could be used to examine explosive reactions which one could not do on a larger scale. It also offers opportunities for point of use synthesis.

Simon highlighted the issues raised by such technology, not least being the interface with the ‘real world’, e.g. blockage, reducing the cost, and detection capabilities. A £1.3 million LINK consortium of 7 Universities and 12 companies is looking at chemistry on a chip – what can be done, and developing the infrastructure for modular systems. Simon concluded: "Miniaturisation will revolutionise chemistry and all associated with it."

Electricity as a way of intensifying processes has been with us for many years, and Alan Heaton of EA Technology told us how Watts ‘power process intensification’ and elaborated on the nine or more electrical processes which could be used as intensification tools. The advantages of electricity were its flexibility, ease of control, point of use delivery, and the fact that it can add value – giving better quality and faster product throughput. The processes include microwave-assisted firing, (e.g. ceramic firing assisted by microwaves overcomes temperature differentials and allows quicker firing and reduced HF emissions. This is generally twice as fast as a conventional oven, but 3-4 times in some cases. Other electric processes include magnetic bed reactors, induction metal heating, radio frequency (r.f.) processing, venturi aeration, enhanced membranes and ohmic heating. Alan described the magnetic bed reactor as an enhanced fluid bed unit, for uses in, e.g. the biotechnology sector. Magnetic particles excited in a fluid bed can enhance throughput, (by up to 4 in one trial) and give better yields. In conclusion Alan said that the electric processes could allow faster, smaller, higher output per unit of energy, and lower inventory processes to be designed and operated.

The Torbed reactor system was then described by Martin Groszek of Torftech. This s essentially an intense gas-solid contacting system, able to undertake gas-solid reactions. It is easy to automate and has a low pressure drop, allowing process gas recirculation. Applications include ore roasting, a unit typically handling 15 t/h of sulphide ore and measuring 4 m high x 3 m diameter, and drying (e.g. chicken litter – allowing a much smaller dryer). GMF in the Netherlands is using the Torbed instead of a prilling tower in fertiliser production. For processing 30 t/h, the original towers are 25-70 m high and 7-25 m in diameter. The Torbed system ranges in size from 6-8 m high and from 2-7 m in diameter. Obviously retrofit becomes easy, and Torbed can be used where the reaction takes place in a few minutes or less. However, if a full understanding of the reaction kinetics is available, longer reactions (hours) may be shortened and carried out in the Torbed.

Martin listed a range of applications, such as catalyst reactivation, gasification/pyrolysis, pasteurisation (clinical waste, herbs & spices), calcination, combustion and desorption.

Before the talk on control, Steve Flynn highlighted that Advanced Control Technology Transfer Programme, where some funding opportunities still existed. The contact point is given as a footnote. Roshan Jhachuck & Ming Tham (Newcastle University) then talked on instrumentation & control issues in PI systems. The overheads are available on the PIN Web site, but some important points are discussed here. The control problems for PI systems are perceived to centre around response times of loop elements, and measurement difficulties. Particular factors influencing the control are for example linearity – it is easier to heat than to control – and time variations, such as catalyst deactivation. Interactions between units up- and downstream need to be examined, and any control system has to be able to implement changes which help the system to return to the status quo as quickly and as smoothly as possible. An important question asked by the presenters was: "Can problems be alleviated by system redesign?" In a PI system, one answer might be to build the control system as part of the process. (See report later on the Control Workshop).

The successful conference in Antwerp, the 3^rd in the series on PI organised by BHR Group, was the subject of a talk by Mark Wood of BHRG. Those who attended (about 90) saw PI as giving capital cost reductions, shorter development times, inherent safety and a route to clean technologies. There were more industrial applications than at previous conferences, and an emphasis on ‘whole plant’ PI. On unit operations Mark said that oscillatory flow reactors can achieve large volume reductions (100 times) while retaining up to 2 h residence times. Compact heat transfer units were becoming more compact, a development to achieve 20,000 cm²/cm³ being mentioned. Rotating systems featured. The history going back to Kodak in the 1930s. Dow Chemicals described a new rotating packed bed process to make HOCl, the existing process being uneconomical. Gas rates are halved compared to the conventional plant, and absorption, reaction and stripping ate integrated in one unit. Mark concluded by saying that in 1997 PI was ‘a solution looking for a problem’. Now PI is coming of age.

Impromptu Presentations: After lunch the impromptu presentations began. Mike Jones ensured that all presenters kept within the specified 5 minutes, and a most useful session was held, kicked off by Mike Lancaster of York University on the RSC Green Chemistry Network. The scope covers sustainable, environmentally friendly clean technologies, including PI, energy efficiency, safer reactions etc. It is funded by the Royal Soc. Chem. Also aims to bring more people into chemistry by involving schools etc. Next, Brian Souliaman described the DENA System mixer/homogeniser/reactor system, the subject of a poster. One feature of the internal structure of the unit was the ability to control shear. John Shaw of CRL introduced his poster – the subject being microchannel & micromesh reactors. Initially CRL was looking at liquid-liquid extractions, under diffusion control. Diffusion lengths were down to 30-50m .

Work at Sheffield University on stacked microchannel reactors was described by Jordan MacInnes. Etched channels in plates were stacked in a cross-flow configuration. The aim is high production rates, where adding droplets/minute can be translated into tonnes/day. The reaction rate is inversely proportional to the channel hydraulic diameter, and is kinetics-limited. Mass transfer controls on larger channels. Jordan gave interesting scaling data for a 30,000 tpa ethylene plant – if d_h was 100 mm, the volume of the reactor was that of a sports stadium! If d_h was 10 m m, the volume would be that of a car boot, (or trunk for our US members)! The length would be large, therefore the reactor would be folded up. Heat transfer intensification was the subject of TNO-MET laboratory (NL) studies described by Henk van Deventer. One was a structured tube for heat exchangers, giving good strength and using less material, and the other was a narrow angle spiral tube which exhibited excellent mixing and heat transfer only a short distance downstream of entry. Terry Winnington of Process Kinetics outlined some of the ‘needs’ w.r.t. PI – industrial champions, good design, reliability, and the movement of equipment from the laboratory into industry, where commercially sensitive data can be obtained. He also felt it was necessary to find the kinetic limits to processes.

Safety was the theme of David Edwards of Loughborough University. Looking at inherent safety, he stressed the need to identify hazards at an early stage, and then to change the design to remove them. This could involve PI. David highlighted ‘indicators’ such as pressure, flammability, toxicity, leading to the concept of ‘scoring a route’ to a product. He illustrated this with the case of methylmethacrylate (MMA), there being 6 routes, the one currently used being the most dangerous! Other work he is doing involves examining the relationship between inherent safety and cost, and an ‘environmental hazard index’. Continuing on the safety theme, Janet Etchells of HSE described her role in the Technology Division, Gas & Chemical Process Safety Unit. In particular, hazards of chemical reactions were cited, there being 10-20 incidents each year, mainly in batch and semi-batch processes. As well as improving standards in existing plant, HSE supports activities in, for example, PI (the spinning disc reactor at Newcastle). Janet invited proposals aimed at inherently safer means, for example PI, of improving the safety of chemical reaction processes. The documentation (Mainstream Research Market Document 2000/01) is available from Fiona Garner. The call is published in mid-February, closing 3 May 2000.

Work at UMIST on process integration and how it can benefit intensification was described by Frank Zhu. As an example, he showed how 3 compact heat exchangers could, using integration methods, replace 11 shell and tube units. The change affects upstream processes such as reactions or separations, and he believes that there are lots of opportunities to use the techniques to eliminate, for example, separation processes. Another example was an LNG plant, currently using compact hx’s. An integrated plant would need 2 (instead of 6) hx’s, with header number reduced from 40 to 34. Frank concluded by observing that: "Better process integration can give the maximum benefit to process intensification". In stating that process intensification may allow us to do things in a better way, Bernard Jones of Kvaerner Water took us through aspects of waste water treatment. In describing the several processes involved in treating waste, he said that one could intensify each unit independently, but the challenge is to put them all in one black box. Bernard asked whether one could extend the biokinetic limits, or design into the process something to improve separation. Enhancement of oxygen transfer rates is also important. After highlighting some common misconceptions about waste water treatment, he said that we need to, and can, make improvements – such as flow sheet integration, plant upgrading (not necessarily total replacement). Technical achievability and economic viability need satisfying in achieving the ‘end point’.

Finally in this session, Elizabeth Foord of EPSRC said that the 11^th IMI (Innovative Manufacturing Initiative) call for proposals was due early in December. A themed call is due in the New Year, (see next PIN News). There is a budget of about £2.5 million pa in IMI, and safety aspects are also of interest.

Workshop: An extensive discussion on control issues in PI was led and effectively handled by Ming Tham, (see above). Here a few observations from those who spoke during the discussion are highlighted, to give the flavour of the subject. While full data on the Workshop will appear in PIN News, any contributions on the subject fromPIN members, for publication in the January issue, are welcome – please Email them to DAReay@aol.com ASAP.

Terry Winnington kicked off by saying that in the Rotex heat pump all control parameters were integrated inside the rotating assembly. Janet Etchells and others stressed dangers in the laboratory, after we heard that control might take second place to proving the technology. Ming said that there was the impression that control was a separate subject, but it is part of process systems engineering. The incorporation of control into process models so that effects could be examined on the computer was interesting to several. How about using control technology from, e.g. aerospace for PI plant, as systems currently used in the chemical industry were generally not appropriate – cross fertilisation, said Terry Winnington.

What are the drivers for control? Ming said that to produce a product to design spec. was important. But there are physical constraints to this. In a comment from the floor, if we have arrays of sensors, the sensor element can become a problem now! Safety is also a constraint. The bottom line is the $! Steve Flynn said that we need to feed PIN control work to other groups.

The human interface needs attention – it was suggested that production personnel should be included in the development team. Richard Poynton said that quality and intensity of training and involvement those running intensified processes was also important.

Minutes of the meeting prepared by David Reay from notes taken during the meeting. Any errors are his!